The phrase "rang up" generally refers to making a purchase or calling someone by phone. There are several synonyms for this phrase that can be used interchangeably depending on the context. For example, "called up" is a synonym that can be used when referring to calling someone by phone. Alternatively, "charged" or "billed" can be used to describe a purchase made by a customer. Other synonyms include "phoned," "dialed," "contacted," "ordered," and "procured." It is important to use the appropriate synonym depending on the situation and intended meaning.