My Metro Pcs Lg Stops Working!

Sometimes when I send messages they just sit there saying "sending" & either takes a long time to send or just wont send at all, Also I have problems with calling, sometimes I can press call & it will do absoltuly nothing!!! Then BAM 10 mins later the call will go through, or if I pushed call more then once, it will call them on both lines & I have to merge the phone calls. Idk what Is wrong with it but it really upsets me... I have unlimmited everything on my phone so its not like I am going over my ussage for the month, & I live in NYC so I basicly have service all the time!! Can someone please help me fix this problem its very frustrating, & what if I need to call someone in an emergancy & the call wont go through!?