ONLT Shower System, LED Thermostatic Shower Set, Spa Spray, Rainfall Shower Head, Bathroom Shower with Hand Shower, 19.5 Inch Chrome Finish Shower Faucet Set(HM-850005)

the shower system is very nice and modern but the water pressure never gets higher than 8.5 litter a minute instead of 16-17 as presented. I tried to contact the company for help but no answer.