Kelly Hemsley tried to take four-year-old Eddie to Knockhatch Adventure Park at Hailsham, but could not park in a disabled bay and found no way to bypass the very long queue.
After a row with staff she was forced to head home, and says she left disappointed and £70 out of pocket.
The park has apologised and said the family arrived on the busiest day the small farm park has ever had.
It is planning to create a dedicated entrance in future for people with disabilies who cannot queue.
But Kelly said she was ‘gobsmacked’ by the attitude of staff towards her son, who is severely autistic, has ADHD and severe global development delay.
The full-time carer said: “I’m so angry and upset.
“We went Knockhatch Adventure Park today [August 18] but didn’t manage to even access the park as there were no disabled parking bays.
“We asked to speak to a member of staff, a lady came out to us and said ‘disabled bays are first come first served, you should have arrived earlier’.”
Kelly said the woman also told her ‘it’s not our fault your son can’t queue, I’m sure there are other children with autism queuing who don’t have a problem’.
She added: “She gave us no other option but to turn around and leave, leaving us £70 out of pocket and absolutely gutted that our Eddie wasn’t able to access the park like others. This is the first time we have ever felt discriminated against because of Ed’s disability.”
Colin Jaggers, managing director at Knockhatch, said: “We are small family Farm Park that has invested as much as possible in making the Park as accessible to all customers as possible. We are dealing with unprecedented numbers of customers due to the current situation post Covid. We can only react when new situations are brought to our attention. We are already looking at creating a dedicated entrance for people with disabilities that cannot queue and are also looking at the most popular rides having this facility too.
“We pride ourselves in being as accessible as possible. We were one of the first parks in the country to install a full and official Changing Places Toilet and during lockdown we have installed an £80,000 inclusive dedicated play area.
“Of course, through the summer holidays we are always busy but after lockdown this year is busier than ever as people who are not able to go away on holidays are utilising parks like ourselves for days out.”
He added that he was ‘very sorry’ the Hemsley family felt they couldn’t enjoy a day out at Knockhatch.
Colin said: “On the day when the family arrived it was the busiest day, we have ever had at Knockhatch Adventure Park, with the only downside, unfortunately the main car park and main disabled parking bays where already full when they arrived.
“The parking attendant tried to help and called the Manager, who explained this to them and explained that there was an overflow disabled car park a very short distance up the road.
“The Hemsley group then because very upset and was very verbally unpleasant to the manager regarding the parking.
“The group also wanted to know if they could jump to the front of the queue and the manager explained to them that unfortunately at this current time, we do not have a fast pass facility and they would have to join the queue like everyone else and again she was met with a barrage of insults, at which time the manager had to walk away.
“We have a zero tolerance for any abuse towards our staff and managers for any situation and when this happens, we stop all conversation and walk away.”
Kelly denied being abusive towards staff. She said: “Hand on heart no cursing language was ever used. My husband spoke in quite a calm term.
“The only words I called out to her were ‘please our son is severely mentally impaired it’s disgusting you can’t do this’.
“I think it’s quite a normal reaction. We were never verbally abusive at all.”