poor service

I have been with this company now for 10 yrs and no complaints so far until recently when thety accidently disconnected me and have told me they gonna charge me £25 reconnection fee. I said i would pay it if they took it off my next bill.  they said yes they will. but when i phoned them up for an engineer to call to my property they want me to pay £100 pre-payment before they will put me bk online but its there fault that they disconnected me in the first place i am now considering going with a different company .