You get better protection if you use your credit card. The key difference is that when you claim on a credit card under Section 75 of the Consumer Credit Act, the credit card company is legally liable.
A pet rat can live between 2-4 years maybe longer it just depends on how well you look after it.
According to the Guinness Book of World Records, the oldest hamster lived for 7 years. A dwarf lab mouse at the Southern Illinois University Cabondale Vivarium lived 4 years 11 months and 3 weeks. The mouse died in January 2003. There are reports about pet rats that lived about 7 years.