Battery said 12hrs and died after 50mins of gps running! Need warranty contact please

Charging seems to rapidly increase to 90% in about 10 mins!! How do I contact you guys about the warranty this is something rather incorrect with this model I have! It’s not living up to any of the stats you mentioned. 
going flat from like 10% no notification to saver modes and was meant to have 12hrs! I have done longer walks on this before on gps but now it’s jsut not am charging it like every 2 days rather than every week!