DELL VENUE 7" TABLET

I purchased a tablet brand new from Best Buy here in Canada, had it almost 6 months so I contacted by phone Dell Customer Service, they told me to send it to them for repairs. They didn't have the part to fix it. Meanwhile I was told it would only take 5 business days to repair, I had emailed them 10 times plus phoned the Tech Dept 6-7 times why they were taking so long to fix my USB port on my tablet.They offered to send me a refurbished one so I accepted. In total by the time I got a tablet back it was almost 3 1/2 weeks later. But the problem with the refurbished one is it's taking over 8 hrs to charge from 50%. I am fed up!  Your Tech Dept is useless, I want a phone number to Head Office not over in India. I am contacting the Better Business Bureau here in Canada to file a complaint against your company. I will also recommend anyone I see whether in a store going to purchases any Dell product not too!!