u/OkSquirrel4830

I've only used morrisons delivery twice and yesterday I received an extra pack of chicken (4.25). It was the only thing in a plastic bag so didn't realise until 20 mins after the driver left. Informed customer service via email. Got a reply today saying to keep it with their compliments (fair enough). Got a separate email saying a refund has been processed for the pack of chicken. I now have 2 free packs of chicken (8.50). Im just wondering if this is common as I haven't had this with tesco the past decade.