Refuse to exchange wrong item

My 14 year old son went into the store to purchase a cable which the sales person assured him would work for the purpose he explained, it was the wrong cable and we took him back to the shop to exchange it.<br> <br> They refused to exchange it because the pachaging was cut open. This is ridiculous and the attitude stank, the sales person was plainly rude and extremely unhelpfull.<br> <br> New world menlyn will NEVER get any business from me again, i will also post it to all my social media sites and the cunsumer protector.