Amazon phone repair - what's going on here then?

My phone's charging port started not working very well after 10 months of ownership. Sent it back for repair under warranty to amazon who said I should receive it back within 2 weeks. 2 weeks have now passed and I have only received confirmation that they have received it. I have asked for an update 3 times now and each time they say the repair centre will get back to me in 24-48 hours - this time passes and I hear nothing.

I sent it to "olympic shaver" something in Notts which looks like it repairs electric shavers, weird place to send a smartphone to.

I'm surprised Amazon are fobbing me off like this. Has anyone had any previous experience of this? Can I get a refund through my credit card I originally purchased it with?

TIA