Hi Nanny,
Welcome to the Mattress Forum! 
I deleted your other post (which is basically a repeat of what you posted here) that you placed in another unrelated forum, and attached it to your original post in this thread. Similar posts across multiple threads make it more difficult for those wishing to learn about and track your particular comments, and also “muddies the waters” of the original topic of those other threads.
With all that being said, I’m sorry to hear that your cover is making you itchy and that some sort of a fiber is migrating out through the cover. There was a thread describing a similar situation here, and you can see my comments and those of a few other members about those fibers and where they could potentially be coming from. Unfortunately, and curiously, there was never a follow-up post in that thread where anyone reported back about any contact with the manufacturer or a resolution to their issue.
My first step for you would be to use some sort of a good mattress protector (with a polyurethane or PVC/plastic/vinyl barrier) around the mattress. I know this will change the comfort of the mattress, but at least for the short term it will stop your contact with those fibers. Once the cover is on, be sure to vacuum around the mattress in case any fibers made their way onto the floor. If any contact was made with sheets or pillows, you may need to shake out those items or wash them as well.
Next, I would contact Spa Sensations directly with your concerns. I would be interested in learning about what they say regarding your situation, and what remedy/resolution (if any) they propose. If you have any photos of the fibers, feel free to post them here in your thread as well.
I hope that you’re able to get some answers and achieve a good resolution to your situation.
Please keep me updated with your progress.
Phoenix