A restaurant in Heathfield was the target of a possible sabotage attempt after its telephone line was cut off.
The owner of Cafe Rosoi was left struggling to make ends meet after his phone number was cut off by British Telecoms (BT).
Is is thought a third party had tried to “take over” the businesses’ phone number.
Businessman Shah Ather said he was several thousand pounds out of pocket after staff were left unable to take bookings and take-away orders at his restaurant for six days.
He said it could have been someone trying to do something to sabotage his business.
He said: “I don’t know whether it was a matter of wires being crossed or someone trying to sabotage by business.
“I got a letter on the 21st of October saying if I didn’t respond by the 24th BT would give my number to someone else.
“But they didn’t give me enough notice, the letter said one of my customers had asked to take over my number and if I didn’t reply by the 24th they would assume I didn’t want it.
“But the first I realised was on the Friday night when we didn’t get phone orders or bookings.
“I’ve managed to get it back after a struggle. It’s been an absolute nightmare.
“No-one could contact us for a week. I’d say we lost a few thousand pounds but also taken a hit on future bookings.
“I was struggling to pay bills the following week because it’s a cash flow business and I have to sign a lot of cheques.
“I’ve shown the letter to customers and they’ve said it’s absolutely unbelievable.
A BT spokesman said the company is currently investigating whether someone had tried to change the phone number from a business to a residential account.