I just stop upload with them for maybe 6 years and just re-start to upload with them recently when they announce the increase in payment rate -not because the increase- but because of the anti-SS movement (i don't get any new sale with DT anyway...).
So, i was far from DT for long time, so i don't know how things change ... but some years ago DT just delete those images that after certain time (1 year or maybe more) don't reach any sale... maybe this is the case...