Solarplicity cds ltd

Massmonster

Hi I keep getting messages from the above claiming I owe money to solarplicity when in fact they owed me and I had to do a reverse direct debit through my bank as I was owed credit and compensation for late final bill and late credit payment. I have emailed them and tried ringing them they keep egnoring emails and just send the same one back rather than explaining reason I now supposedly owe money. I got to them on the phone once and I explained everything to be told by the lady that no such compensation laws exist. Itold them it was an ofgem rule and she hung up on me. They have sent me a final bill finally a year since I left them as I never received one. All the messages and final bill are by email tho nothing via post. The final bill makes no sense saying I'm in credit at the beginning then suddenly I'm in debt the exact amount I got with my indemnity claim but no mention of compensation being paid. I technically am owed £10 still as can only claim the exact direct debit amount back. Any ideas who I can speak to about this as they don't reply themselves or lie about the laws.