The government should view this as a warning, said FF Plus MP Anton Alberts.
"It is clear that the public is despondent and battered by what they view as unreasonable action by the state," he said in a statement.
Three incidents have been reported at Sanral's building in Midrand.
On Sunday, the building had to be evacuated after a bomb threat. No bomb was found.
It was also evacuated on Tuesday and Friday after a suspicious powder, initially thought to be anthrax, was found.
At the time, CEO Nazir Alli said the evacuations had not compromised the toll collection process, and that the toll gantries remained operational.
Alberts said on Monday that the party was prepared to help people report their problems with the toll system to the National Consumer Commission (NCC).
"We invite the public to make use of these legal channels to show their opposition to the e-tolls," he said.
"The NCC has the right to see to it that all problems are resolved. While a complaint with the NCC is pending, Sanral is not allowed to take any legal steps or any other steps against a person."
This meant Sanral did not have to be paid while a case was pending, Alberts said.