"I bought some pvc supply and extraction…"

I bought some pvc supply and extraction valves £15 each and totaling £90, beware ! If you fit these and try to remove them later for cleaning ect the small metal prongs that hold them in place will break off Rendering them useless, there is no information on the website informing you of this, I complained to Gary Burns of BPC and informed him they were only 3 months old and he sent me a very nasty email telling me to send them to airflow and not him !
I have purchased a complete Mvhr system from BPC costing thousands of pounds and as soon as I need help it simply isn’t available, the customer care is non existent