New DNA sample required

[Tom Tom]

I bought an ancestry DNA kit for my Grandmother earlier in the year. Was really easy to do and the results came back within a couple of weeks.
In the summer, I ordered my dad a kit. Waited weeks and weeks after sending it back and then got an email saying a new sample was required and to order a new kit.
We ordered a new kit and sent it off. More and more waiting and then got the same email saying that a new sample was required.

Dad assured me he did it all properly and followed the instructions to the letter.

We have now ordered another replacement kit.

Does anyone else have experience of this?

Thanks.