Extremely disappointing experience

Went to Steves Spar in black heath. .and am feeling so dissapointed...bought stewing lamb .. (thats what l thought l had bought) the meat is as tough as hell...stinking too...tried to spice it up to cover the smell..but am 100% sure we being sold mutton as lamb...after two hours on the pot..it still the smell l could taste it...the service of cashiers..is just for another day...