Hello Beyoden. If the shop includes the purchase of an item which will be reimbursed, you will have to submit a scan or photo of the receipt. This ties the purchase to the mystery shop.
If you are not allowed to return the item and you do return it anyway, your return transaction may flag as being associated with a mystery shop. What can happen is that you will lose the option of shopping with that mystery shopping company in the future.
I am not saying this will always happen. I'm saying it can happen, and if they are telling you not to make a return, they care. They probably care enough to track it.
As far as the reasoning goes, I can only guess. Say the shop pays $10, and the reimbursed purchase allowance is $6.00. You buy a $6.00 item, which costs the client less than $6.00. Something less than $16.00 is paid out to the shopper.
The client does not want to take back a $3.60 cost item, pay a cashier to process the return, pay a floor person to restock it, and give you $6.00 cash.
This increases the cost of the shop considerably.
It's not worth the risk. It would be better to skip the shop if you find the guidelines unattractive, and concentrate on other jobs the company may offer.
Mary Davis Nowell. Based close to Fort Worth. Shopping Interstate 20 east and west, Interstate 35 north and south.