Data plan for USA

[#1]

In the USA and had to deal with something urgently involving phone calls and SMS back to the U.K. upped my smart cap to the £30 max. I’ve used all that up in just one morning. Is there a way of adding something to my plan that will give me US calls or allow me
To go beyond the £30 max smart cap?

Because now all non WiFi services ade disabled because I’ve hit the max £30 limit and can’t take/make any more phone calls/SMS on my Plusnet SIM.

[#2]

Hi there, we don't offer a specific data plan for overseas use but we can increase the smart cap for you and I hope everything is OK back home. 

Feel free to send me a private message with your full name and mobile number and I'll be able to sort that out for you. 

Apologies or us taking a few days to pick up and reply to your post by the way.