Depending on the product, Microsoft may repair the device or send a refurbished replacement. If you get a replacement, it will have a post-service warranty of the remainder of your original period or 90 days after shipping, whichever is longer.
Ref: How to get service or repair for Surface
Check the service order status in your Microsoft account (the warranty and service section) and note the service order number.
Check whether it shows “received at service centre”, “in repair” or “shipped”. Tracking details appear once it ships.
If nothing changes after about 10 to 14 days, contact Microsoft Surface support with the service order number and ask for an escalation and an estimated return date.