A new build served overhead suggests it’s an infill property in an overhead area , or a very small development , again in a predominantly overhead fed area, did the developer of this property ever approach OR about FTTP ?
If the duct runs to the base of a pole , and assuming this pole is in a public footpath, who provided the last part of the duct , as a ‘developer’ shouldn’t be excavating in public land , if it’s an OR pole, OR or an OR contractor should be linking up any developer installed duct , not the developer, the developer should only go to the site boundary/curtilage.
If the general area has been provided with a fibre overlay ( you state that fibre is already at the pole ) then is your individual property shown as having FTTP available on the BT Wholesale checker , perhaps you can show the results for your individual address from
https://www.broadbandchecker.btwholesale.com/#/ADSL
If your property isn’t listed, or didn’t exist when the area was surveyed for FTTP, then it’s possible that you ( at least initially) can only order a copper pair service ..no point in arguing with the OR installer, if the job has a ordinary exchange equipment and a copper pair routing, that’s what you will get,( or you refuse the install) but the OR tech cannot arbitrarily just provide ‘fibre’.
Even if there is fibre to the pole , presumably you know this because there is evidence of FTTP , like a CBT (connectorised block terminal) , but if your address has been added after the area was dimensioned for FTTP) and assuming FTTP capacity is available , your address may need to be added before FTTP is shown as available.
