Overseas applications shafted?

I have been through a few hours and many calls on the phone now with HMPO (or the call centre at least), but to no avail. A bog standard Adult Renewal application from overseas was marked as received on 23rd March, with no further updates over a month later. A few helpful call centre people did indicate that overseas applications are in a separate queue (one mentioned with paper applications). All claim there is no way to get an overseas application upgraded — that seems to be borne out by the information on the HMPO website. I have already had to cancel a trip this week. I have more work travel in 2 weeks and in mid June, which is all important. How 10 weeks has become an acceptable benchmark for a standard passport renewal when colleagues from Europe and North America are getting their passports renewed in a week or two is beyond me. I note that overseas applicants also bore the brunt of delays last summer from previous posts here. I have tried to get call-backs from the passport office which worked 2 weeks ago but not recently. I have tried emailing various email addresses I found on here, all of which now claim to be inactive or unmonitored. Does anyone have advice on how I might be able to get this unreasonably long queue to be looked at?