2 Month Refund waiting period

I Have booked in a laptop and had battery replacement, after a month to find out that the battery health showed not perfect state and it didn't last as long as it should. I then contacted part serve they booked my unit in and 2 months later still awaiting my refund of the the battery I purchased from them. Partserve are one of the most unprofessional companies I came across and refuse to do any further business with them.