Stop buying equipment from Takealot - the products from their suppliers are of shocking quality

Do not trust Takealot suppliers!!!! We recently bought a new powerbank Model P-05 rated at 20000mAh. Before usage we charged it for 2 days and made sure its fully charged. It indicated that it is 100% charged. We then used it to charge a cell phone. The powerbank immediately dropped its charge status to 50% and when the cell phone was plugged in, and was fully dicharged when the cellphone was only charged a mere 20%. How can this be called a 20000mAh powerbank???? What a piece of ******* Takelalot sell. Never used to be like that. Do no longer buy equipment from takealot.