First Utility -advice required please

Dandy_Don

I annually receive a duel fuel discount circa £200 paid to me by cheque every December from First Utility, however they have withdrawn it this year due to an "outstanding debt".
My problem started about 1 year ago where my gas meter had stopped "clicking", I immediately advised FU who sent an engineer who travelled approx 140 miles to fit smart meters for both my gas & elec but turned up without the tools to install the gas meter but did install the elec meter. Approx 1 month went by & I did not hear back from FU to advise when my smart gas meter would be installed so I emailed them & they apologised for not giving me the service I should of received & said another engineer would be sent. Another few months had past during which time I submitted my exact gas reads as per my old meter on time each month. I had also sent a email chasing them up & complaining about the service but I have never received any reply! Back in August I called to query a rather high gas reading on my bill only to be told "there seems to be a problem as you keep submitting the same gas reads each month!!!!" (Tell me something I don't know!) at this point an engineer was swiftly deployed & I now have my smart meter 8 months after advising them of my problem but they have decided my annual £200 cheque will not be sent this year! Should I have to pay this "outstanding debt" due to First Utilities incompetence & me being honest throughout? Please help.