Before you get in contact, please follow the basic troubleshooting steps.
https://support.bestwayaftersales.co.uk/faq/get-help-with-your-lay-z-spa-pump/
If troubleshooting doesn't seem to fix things (it often does) and you want to get in touch to lodge a warranty claim, don't immediately pull it to bits to return the spa. We don't have testing facilities here at the warehouse, and Bestway (the supplier) is very good at fixing things and directly sending out replacements if a fault is found.
So - to speed up the process (because we know what the manufacturer will be asking for) - film a short video of the issue and grab a photo of the serial number on the unit.
We don't have many spares and can't provide servicing in house for these spas, sorry.