Did you have any end and relist during the 150 promo time? If so, how thoroughly did you check? It's easy to miss a couple here and there. 

If you've been getting the free 150 for years and they've never come off your auto relists, you are very, very lucky.

Btw 'it's a glitch' is a common answer for ebay for a whole myriad of problems. It may well be a glitch, but it's been glitching for a couple of years now, so don't hold my breath that it'll ever be fixed.