[unable to buy mainland]

ok heres the situation...i have paid three months subscription. i have been paid up for over a week now. i want to buy mainland.

i can search land the option to put in a bid allows me to do that.

i place the bid but when i click bid it says i have to upgrade. eventhough i am only bidding on a 512 teir which i can buy as a premium member.

i have left messages with linden avitars, sent a ticket in and still no reply from anyone. any help here at all please would be very nice.

thank you