"I'm scared to use the wheelchair"

I am a double amputee and I am 86 years old and suffer with arthritis.  WestMARC delivered me a motorised wheelchair, the engineer fitted the footplates and the cushions but it wouldn't work or move.  They took it outside for over half an hour but still wasn't working properly. They said the battery was ok probably just needed to be charged.  I don't think they knew what they were doing. 

It seemed to start to work after a while.  I used it a couple of times but one day I was using the chair in the hallway when it cut out and I was left stuck there unable to move anywhere for two hours until my daughter could get to me.  We phoned WestMARC who came out to look at the chair and they said it must be my own fault and that I must have banged it because apparently if you bang or knock the chair it will automatically cut out.  No one told us that and I am not sure if that is  true, we were given no prior information.

It's now stuck in my spare room as I am scared to use it I don't want to be stuck in it again.

I rang WestMARC to complain but they gave me another number and told me to give my complaint there.