I have had a very similar problem mine was that i kept losing service and still do and was told by a Talk Talk rep was an "intermittent" fault and that there was nothing they could do and was given all the info on call out charges but was told by the rep that it was unlikely that i would be charged if there was no damage to equipment or wiring in the property. no damage was found but as defined by the word INTERMITTENT the fault is not always present and as expected it was not present when the engineer came out.
i was then surprised to find that i was being charged for the call out because no fault was found. i disputed the fee the rep i spoke to said he listened to the calls and that because the fee was explained i would be charged. and the fault is still plaguing us but we aren't willing to have an engineer out again as we can't afford another £65 for nothing.
following this disaster and it being just after Christmas that they informed me of the fee i had to agree to a payment plan of my bill + £10 to clear the unwarranted fee. but have been receiving text messages, letters, calls, and emails almost every day demanding payment. i have called and called explaining that i have a payment plan agreed and still keep getting these calls. i have called today after a text stating that my service has been restricted. the rep i spoke to said that there were no restrictions and that it is basically a threat to pay or they might restrict it. so the text is in effect a lie.
i have now contacted the Ofcom due to this confirmed threat and lie. and because of the persistent nuisance that talktalk is causing and i can't wait for my contract to expire so i can get away from these con artists.