anyone of you guys have multiples exposure limit of 10,000?

Few guys in the forums have multiples exposure limit 10,000 and I want to have my limit increased to 10,000 too but Betfair keep ignoring me when after first try they denied my request. First time they denied saying that they cannot provide any reason why, second time they ignore my mails. Is there no chance for me to get my limit increased? how much more will I remain so tightly limited?