New build - water meter not found

Hi, we moved into a new build last winter and on the moving day we were due to sign off the meter readings to transfer them from the developer to us. The problem came when the developer was unable to find our water meter, believing it to have been landscaped over so they told us that their onsite team would come and sort it out.
We never heard from them and then recently our water company knocked on our door trying to take a reading. They were unable to find the meter too and now their next level of meter reading team are also unable to find it despite coming equipped with a metal detector and shovel. The next step will be to dig up our garden in the rough area of where they think that the meter is placed, I'm not sure if this will be by digger or manually.

My questions are - since this is due to the developer (or their subcontractor) landscaping over our meter, and therefore not being able to sign it over to us, are we fully liable for the charges on the account given that no initial reading was given? Obviously I'm happy to pay for what we've used but only if it can be proven that we used it. Secondly, if our garden is to be dug up, who would be responsible for leaving it in the condition in which it was found? Currently there are lot of large shrubs (not planted by us) in the area where the meter is suspected to be and I don't want to be out of pocket having to replace them.