Complaint

I bought parts a week ago, and unfortunately they were offline so i didn't receive a slip and i heard the customer that was in front of me was asked about his email address so that they send him a slip, when it was my turn i wasn't asked about email address When i got home the mechanic told me they aren't parts of my car so i had to return them Now im told that i didn't even pay for those parts, after driving and wasting my time because maybe if i had a slip i wasn't going to take them back anyways because it was going to keep it i mean Christmas comes once a year I did engage with the sales person to atleast compensate me then though i wasn't trying to be a good Samaritan I have a slip that says i retuned the parts