I rescued a 11 hh welsh sec A?

It was running up a busy road, the police were on the scene and they notified the rspca. I kindly said i would keep the stallion on my field with my gelding. for a short period of time until the rspca came to get him. The rspca did not come. The police told me the horse would be mine after 21 days. They since found out this stallion has been abandoned by travellers. I did not want this stallion as I have two other mares else where with which i need to bring back to my field. I feel totally let down by the rspca. I have no pport. What would you do?