Sky's diabolical service . . .'

I've been a Sky customer since January 2017. Up until 2 weeks ago, I had intermittent TV service. Many phone calls to Sky were made and then visits from engineers who fixed various issues (supposedly) with the dish, the wiring, the box, etc, etc. On the penultimate phone call to Sky last month, I was told it was actually a software issue and to wait a couple more weeks in order for my problem to be fixed. I have done this and things now seem ok and I can actually turn on Sky and watch something - amazing! Last week I thought I'd phone Sky and ask for some recompense for all of the months I have had no service and have had to resort to watching Freeview . . . . Would you believe they have no records of most of the calls I have made to them and had the cheek to offer me £12. I've refused and asked to put a complaint into the complaints department. I was told I would have a return call within 72 hours. I am still waiting! Has anyone else had this software issue?