Mobile Telecommunications Expert Advice

I need a telecommunications expert to answer the below questions. Regarding Mobile phone networks, when there’s excessive congestion: a) What do the telco providers do with users sent messages. Are they queued indefinitely? Or if the congestion is insanely excessive, would they delete them at some point? b) Is there a way to get messages from one user to another quickly during these times? For example can you buy priority bandwidth? If so how does that work when the sender and receiver of the message are on different networks to me, given that I need to ensure the transmission? Could an app be configured to send the message through a network that I buy this priority bandwidth from, irrespective of the senders/receivers networks?