Poor customer service

I am so frustrated with Blue security alarm malfunctions. Just last month they said there was a fault with batteries on both my alarms which I paid for them to replace. and besides that they had to come out 3times for one that was still malfunctioning as they indicated they were getting distress signals on their side. The same is happening again this month on the 2nd alarm I paid for them to replace the battery last month. They came and did not even indicate what was done or got my authorisation for whatever they did. The coordinator I spoke to said they will send someone but will only charge for the work they need to do if there is any fault other than the battery as I specifically that I will not pay for all these call outs as their staff came out last month. With no communication I just got an invoice of R614. The technical team could not tell me what was done when I enquired telephonically.