Harley Benton Valuestrings Bass 40-95

I have a Status Washburn S1000 Bass (yes I know very 1980's!) which is headless - I've recently tried these budget strings with it (the bass has allen key 'clamps' to hold the strings at the head and tuners at the bottom of the bridge - in common with most headless basses). At first they fit well and sounded decent - hence 4 stars for s0und - and seemed like a good purchase, however about a week after fitting them the low E and A strings have unwound under tension at the headstock end and are now completely useless. I have never experienced this with other string makes, and I've had this particular bass for nearly 35 years... So if you're thinking of using these on a headless bass you may want to look elsewhere!