hotpoint aquarius TDL52 Tumble Dryer banging?

I have had this machine for approx 4 years with no problems. Last week whilst drying a loud banging noise started, this happens where the drum indents. I have taken off the top the belt is in place I have turned it by hand and it and it seems that the drum is loose and is hitting a metal strip on the bottom at each indent as tho the drum isnt supported enough. I thought maybe the bearings had gone (I have no idea what this would sound like) but I am wondering if maybe the belt has just stretched causing it to catch the bottom, however there is "movement" on the drum. Could anyone advise?? I cant get anyone to look at it as I brought it with me to Australia and they dont deal with hotpoint here and I dont want to shell out for a new one if its just the belt as I can buy on-online. Thanks in advance hope this makes sense!