Computer inks woe

unsure

Hope this is the right place. I've had terrible trouble with some ink cartridges from inkredible.co.uk and I'm wondering if others have too. I bought two replacement sets of inks for Brother DCP 120c (all in one). It had worked fine on original inks and first set of compatibles bought from shop. After MSE recommendation I tried Inkredibles.co.uk and I've had nothing but trouble. The printer keeps losing quality and needs constant cleaning (20 times consecutively this morning to get black back to reasonable quality!!) in addition ink cartridges don't seem to last as long and printer says "nearly empty" and "empty" when there is still clearly ink left in the cartridge(s).
I guess I'm wondering if I'm doing something wrong (though it's hard to see what it could be!), whether I've just been unlucky, or if it's poor quality and this outfit needs a health warning for MSE'rs.

Inactive

I use the same 900 Brother Cartridges, I get mine from ChoiceStationery, never had any problems with them.