You're a Pattern Day Trader as per trading rules. See below.
From the Financial Industry Regulatory Authority (FINRA) website:
Summary of the Day-Trading Margin Requirements
The rules adopt a new term "pattern day trader," which includes any margin customer that day trades (buys then sells or sells short then buys the same security on the same day) four or more times in five business days, provided the number of day trades are more than six percent of the customer's total trading activity for that same five-day period. Under the rules, a pattern day trader must maintain minimum equity of $25,000 on any day that the customer day trades. The required minimum equity must be in the account prior to any day-trading activities. If the account falls below the $25,000 requirement, the pattern day trader will not be permitted to day trade until the account is restored to the $25,000 minimum equity level
You can flip twice the same day, just so long as you either a) have $25,000 of equity, b) you don't exceed 4 flips in a 5 day period, or c) those trades account for less than 6% of your total trading activity.
I don't know what the solution is if you don't have the funds, but E*Trade is not only within their rights, but is required to take the action they have.
Someone else please correct me if I'm wrong. Best of luck though in getting this sorted out.
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