I vaguely recall from long ago days when I was more involved in such things that there is a regular format and there is a low level format.
On a new empty drive the low level format only had to be done once and was usually done by the Manufacturer before it is shipped to the distributor/user.
After it has been low level formatted then from that time on it only needs to be regulerly formatted, if it needs to be formatted at all because regular format does not remove the low level format.
I don't know if this is still the case but if it is then you need to do a low level format and I have forgot how to do that.
Email the manufacturer and ask them.
Hope this helps,
Bebop