I bought a drive belt for this saw last week from Axminster, their part number is 200145 Drive Belt 501196 AW10BSB2 Saw Bench A-860. The A-860 is marked on the belt which is a standard V type. Axminster charged £2.75 + VAT so I doubt that you will find it a great deal cheaper elsewhere; although as I picked it up I don't know about their postage costs.
As an aside, I bought a random mix of spares for the saw all of which were in stock and all very reasonably priced in my opinion. The service was extremely helpful, very patient (I'm no saw expert) and friendly despite it being lunch time and they were busy. I will certainly be buying more from Axminster when I finally learn what I actually need.
As already advised, the reason for the shredding should be sorted out first. While my original belt has stretched a bit and there is no more adjustment available there is no sign of any rubbing or break up of the belt at all.
Regards
Keith